[Qemu-devel] Fix for accept

[Pablo Virolainen <Pablo.Virolainen@nomovok.com>]

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Following code crashes qemu user emulation.

#include <sys/types.h>
#include <sys/socket.h>

int main() {
        accept(0,NULL,NULL);
        return 0;
}

Pablo Virolainen

[-- Attachment #2: accept.patch --]
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Index: linux-user/syscall.c
===================================================================
RCS file: /sources/qemu/qemu/linux-user/syscall.c,v
retrieving revision 1.75
diff -u -r1.75 syscall.c
--- linux-user/syscall.c	27 Jun 2006 21:08:10 -0000	1.75
+++ linux-user/syscall.c	13 Jul 2006 10:18:57 -0000
@@ -878,9 +878,20 @@
             int sockfd = tgetl(vptr);
             target_ulong target_addr = tgetl(vptr + n);
             target_ulong target_addrlen = tgetl(vptr + 2 * n);
-            socklen_t addrlen = tget32(target_addrlen);
-            void *addr = alloca(addrlen);
-
+            socklen_t addrlen=0;
+	    /* Just to get rid of compiler warnings */
+	    ulong addrt=0;
+            void *addr;
+	    
+	    get_user(addrlen,&target_addrlen);
+	    get_user(addrt,&target_addr);
+	    
+	    if (addrt!=0) {
+	        addr = alloca(addrlen);
+	    } else {
+	        addr = NULL;
+	    }
+	    
             ret = get_errno(accept(sockfd, addr, &addrlen));
             if (!is_error(ret)) {
                 host_to_target_sockaddr(target_addr, addr, addrlen);